Carbon-metal structure and method for manufacturing carbon-metal structure

Abstract

It is a CNT device (1) (carbon-metal structure) equipped with a carbon nanotube layer (2) (CNT layer 2; same hereafter) on a metal pedestal (4). The metal pedestal (4) is brazed to the CNT layer (2) with a brazing material layer (3) interposed therebetween. When manufacturing the CNT device (1), firstly, the CNT layer (2) is formed on a heat-resistant textured substrate (6). Next, the metal pedestal (4) is brazed to the CNT layer (2) that is on the heat-resistant textured substrate (6) with the brazing material layer (3) interposed therebetween. Then, the metal pedestal (4) (and the CNT layer 2) is peeled off the heat-resistant textured substrate (6) to transfer the CNT layer (2) from the heat-resistant textured substrate (6) to the metal pedestal (4).

The invention claimed is: 
     
       1. A carbon-metal structure, comprising:
 a carbon film layer containing a fibrous carbon; 
 a brazing material layer that is directly provided on the carbon film layer; and 
 a metal pedestal that is provided on the carbon film layer with the brazing material layer interposed therebetween, 
 wherein the brazing material layer has a multilayer structure having a first brazing material layer that is formed on a side of the carbon film layer and a second brazing material layer that is formed on a side of the metal pedestal and has a melting point lower than that of the first brazing material layer. 
 
     
     
       2. The carbon-metal structure as claimed in  claim 1 , wherein the carbon film layer has on a surface thereof a texture having an average height of 1 μm to 100 μm and a height/spacing ratio of 1/5 to 5/1. 
     
     
       3. The carbon-metal structure as claimed in  claim 1 , wherein the carbon film layer is a layer that is preformed on a substrate, and
 wherein the brazing material layer is a layer formed on an end portion of the carbon film layer that is on a side opposite to a surface in contact with the substrate. 
 
     
     
       4. The carbon-metal structure as claimed in  claim 1 , wherein the brazing material layer is a layer formed of a metal brazing material, and
 wherein a mixed layer that is the carbon film layer impregnated with the brazing material that forms the brazing material layer is formed at an interface between the carbon film layer and the brazing material layer. 
 
     
     
       5. The carbon-metal structure as claimed in  claim 1 , wherein the brazing material layer has a thickness of from 1 μm to 50 μm. 
     
     
       6. An electron emitter comprising the carbon-metal structure as claimed in  claim 1 . 
     
     
       7. An X-ray tube comprising the electron emitter as claimed in  claim 6 . 
     
     
       8. A method for manufacturing a carbon-metal structure, comprising:
 forming on a substrate a carbon film layer containing a fibrous carbon; 
 forming a brazing material layer on the carbon film layer formed on the substrate; 
 brazing a metal pedestal to the carbon film layer with the brazing material layer interposed therebetween; and 
 removing the substrate from the carbon film layer, 
 wherein the brazing material layer has a multilayer structure having a first brazing material layer that is formed on a side of the carbon film layer and a second brazing material layer that is formed on a side of the metal pedestal and has a melting point lower than that of the first brazing material layer. 
 
     
     
       9. The method for manufacturing a carbon-metal structure as claimed in  claim 8 , wherein the brazing material layer contains a metal brazing material that is vapor-deposited on the carbon film layer. 
     
     
       10. The method for manufacturing a carbon-metal structure as claimed in  claim 8 , wherein the carbon film layer is formed on the substrate by a chemical vapor deposition. 
     
     
       11. The method for manufacturing a carbon-metal structure as claimed in  claim 8 , wherein the substrate removed from the carbon film layer is reused as a substrate on which a carbon film layer of another carbon-metal structure is formed. 
     
     
       12. The method for manufacturing a carbon-metal structure as claimed in  claim 8 , wherein a plurality of metal pedestals are brazed to the carbon film layer with the brazing material layer interposed therebetween. 
     
     
       13. A method for manufacturing a carbon-metal structure, comprising:
 forming on a substrate a carbon film layer containing a fibrous carbon; 
 forming a brazing material layer on the carbon film layer formed on the substrate; 
 brazing a metal pedestal to the carbon film layer with the brazing material layer interposed therebetween; and 
 removing the substrate from the carbon film layer, 
 wherein the substrate has on a surface thereof a texture having an average height of 1 μm to 100 μm and a height/spacing ratio of 1/5 to 5/1. 
 
     
     
       14. The method for manufacturing a carbon-metal structure as claimed in  claim 13 , wherein the brazing material layer contains a metal brazing material that is vapor-deposited on the carbon film layer. 
     
     
       15. The method for manufacturing a carbon-metal structure as claimed in  claim 13 , wherein the carbon film layer is formed on the substrate by a chemical vapor deposition. 
     
     
       16. The method for manufacturing a carbon-metal structure as claimed in  claim 13 , wherein the substrate removed from the carbon film layer is reused as a substrate on which a carbon film layer of another carbon-metal structure is formed. 
     
     
       17. A method for manufacturing a carbon-metal structure, comprising:
 forming on a substrate a carbon film layer containing a fibrous carbon; 
 forming a brazing material layer on a metal pedestal that supports the carbon film layer formed on the substrate; 
 brazing a metal pedestal to the carbon film layer with the brazing material layer interposed therebetween; and 
 removing the substrate from the carbon film layer, 
 wherein the brazing material layer has a multilayer structure having a first brazing material layer that is formed on a side of the carbon film layer and a second brazing material layer that is formed on a side of the metal pedestal and has a melting point lower than that of the first brazing material layer. 
 
     
     
       18. The method for manufacturing a carbon-metal structure as claimed in  claim 17 , wherein the carbon film layer is formed on the substrate by a chemical vapor deposition. 
     
     
       19. The method for manufacturing a carbon-metal structure as claimed in  claim 17 , wherein the substrate removed from the carbon film layer is reused as a substrate on which a carbon film layer of another carbon-metal structure is formed. 
     
     
       20. The method for manufacturing a carbon-metal structure as claimed in  claim 17 , wherein a plurality of metal pedestals are brazed to the carbon film layer with the brazing material layer interposed therebetween. 
     
     
       21. A method for manufacturing a carbon-metal structure, comprising:
 forming on a substrate a carbon film layer containing a fibrous carbon; 
 forming a brazing material layer on a metal pedestal that supports the carbon film layer formed on the substrate; 
 brazing a metal pedestal to the carbon film layer with the brazing material layer interposed therebetween; and 
 removing the substrate from the carbon film layer, 
 wherein the substrate has on a surface thereof a texture having an average height of 1 μm to 100 μm and a height/spacing ratio of 1/5 to 5/1.